As a fluid controller which is used for continuously repeating opening and closing operations, one referred to as a direct touch-type diaphragm valve is known (Patent Literature 1).
Such a fluid controller is of an air driven type, is often used in a semiconductor manufacturing apparatus, and is required to be able to be used at high temperatures and to have a high durability. In addition, such fluid controllers are commonly used for a plurality of lines, and in this case the difference in flow rate (Cv value) among gas lines is required to be reduced.
Patent Literature 1 proposes setting of a vertical movement amount of a stem (diaphragm displacement amount) in association with opening and closing operations to a predetermined value in order to secure the durability (the number of continuous opening and closing operations).